“Who am I?” André Breton demanded in the opening lines of his novel Nadja (1928). “Perhaps,” he suggested by way of an answer, “everything would amount to knowing whom I ‘haunt.’” The same could be said of the notoriously elusive medium of photography, which, like Breton, stubbornly resists all attempts at categorization. “I am whom I haunt”: This is clearly the definition of photography at which Roland Barthes arrived in Camera Lucida (1980), his quest to discover the medium’s noeme or essence through its ability to summon the spirit of his dead mother by offering an indexical trace of her once living presence.

Although they are never mentioned in Barthes’s account, one imagines he would be sympathetic, even susceptible, to the nineteenth-century spirit photographs that are currently exerting a strong fascination on a broad spectrum of the photographic communityfrom seasoned curators